The technique relies on an undisclosed “mathematical breakthrough,” say researchers Erik Tews and Martin Beck, and breaks the Temporal Key Integrity Protocol (TKIP) key used to encrypt data between a wireless router and its clients. Currently, the attack works only one way: data traveling from the access point to its clients is vulnerable, while data traveling in the opposite direction is not.

The only other known, effective attack against a WPA connection relies on computationally-intensive dictionary attacks, which involves testing wireless data against an extremely large list of educated guesses until one of them successfully decrypts the data in question.

Tews and Beck’s attack lowers these requirements considerably, allowing anyone with the knowledge, a laptop, and 15 minutes of time the ability to listen in on one side of a WPA-encrypted wireless connection.

CNet notes that Tews is no stranger to wireless hacking, as he also co-authored a 2007 paper (PDF) discussing how to crack a 104-bit WEP key in 60 seconds.

The duo will reveal their findings at next week’s Tokyo, Japan-based PacSec security conference in a presentation titled, “Gone in 900 Seconds, Some Crypto Issues with WPA”.

According to PC World, some of the pair’s research already is already appearing in wireless security tools.

Companies and internet users looking to keep their wireless networks secure will have to upgrade to WPA2 now, says PacSec organizer Dragos Ruiu.

“Everybody has been saying, 'Go to WPA because WEP is broken,'” he said. “This is a break in WPA.”

While it is too early to tell how the WPA attack will be exploited by criminal organizations, many companies are still in the process of transitioning to WPA from weaker standards like WEP, or no encryption at all. Hackers hit one such company, T.J. Maxx, in January 2007 from secured WEP access points; they ran off with one of the largest credit-card hauls in history and caused more than $200 million in damage.

"Google fired a shot heard 'round the world, and now a second American company has answered the call to defend the rights of the Chinese people." -- Rep. Christopher H. Smith (R-N.J.)